Outside corner clamp for prefabricated wall forms



y 1959 A. ARRIGHINI ET AL 2,896,3(20

OUTSIDE CORNER CLAMP FOR PREFABRJ ICATED WALL FORMS Filed June 15, 1953 4 Sheets-Sheet 1 y 3, 1959 A. ARRIGHINI ET AL 2,896,300

OUTSIDE CORNER CLAMP FOR PREFABRICATED WALL FORMS Filed June 15, 19's:

4 Sheets-Sheet 2 w wwg y 1959 A. ARRIGHINI ETAL 2,896,300

OUTSIDE CORNER CLAMP FOR PREFABRICATED WALL FORMS v Filed June 15. 1953 4 Sheets-Sheet 3 m m W m 2,896,300 OUTSIDE CORNER CLAMP FOR PREFABRICATED WALL FORMS Filed June 15, 1953 July 28, 1959 A. ARRIGHINI ET AL 4 Sheets-Sheet 4 A Tram/vars United States Patent O OUTSIDE CORNER CLAMP FOR PREFABRICATED WALL FORMS Artil Arrighini, Detroit, and George A. Van Sickle, Mount Clemens, Mich., assignors, by mesne assignments, to Rocwall Company, Detroit, Mich., a corporation of Michigan Application June 15, 1953, Serial No. 361,557 Claims. (Cl. 25-131) This invention relates to corner clamps for prefabricated wall panels of the type used in pouring composition walls.

Prefabricated forms for composition Walls usually comprise two laterally spaced series of panels wherein the panels in each series are arranged in end to end relationship and wherein clamps are provided for removably holding adjacent panels in place. Various different arrangements have been used for clamping the panels in place but none of these arrangements have proved satisfactory and this is especially true of the means available to the trade for securing adjacent angularly related panels together at both the inside and outside corners of the form.

With the above in view, it is an object of this invention to provide clamps which render it possible to not only expedite assembly and disassembly of the angularly related panels defining the corners of the form but, in addition, prevent any possibility of spreading of the panels at the corners of the form during the pouring operation.

It is another object of this invention to provide a corner clamp rendering it possible to firmly secure one corner panel in abutting engagement with an end of the adjacent corner panel and to accomplish this result regardless of the extent to which the first named panel overlies the end of the second mentioned panel. This is an important feature in facilitating erection of the form because it enables varying the length of the wall embodying the overlying panel to an extent approximating the width of the end edge of the adjacent corner panel and thereby eliminates the former practice of inserting fillers or spacers between adjacent ends of the panels to compensate for fractional wall dimensions.

It is a further object of this invention to provide corner clamps of the above general type composed of a relatively few simple parts capable of being readily assembled to provide a unitary or self-contained structure. The foregoing as well as other objects will be made more apparent as this description proceeds especially when considered in connection with the accompanying drawings, wherein Figure l is a fragmentary perspective view of one corner of a prefabricated form for composition walls and illustrating an outside corner clamp embodying the features of this invention;

Figure 2 is a fragmentary perspective View of the corner shown in Figure 1 and illustrating the clamp incorporated for removably securing the inner wall panels together at the inside corner of the form; r

Figure 3 is a fragmentary cross sectional view through a prefabricated wall form at one-corner of the latter;

Figure 4 is a sectional view taken on the line 4-4 of Figure 2;

Figure 5 is a sectional view taken on the line 55 of Figure 2;

Figure 6 isa sectional view taken on the line 66 of Figure 3;

2 Figure 7 is a sectional view taken on the line 77 of Figure 3;

Figure 8 is a sectional view taken on the line 88 of Figure 2;

Figure 9 is a sectional view taken on the line 9-9 of Figure 3;

Figure 10 is a fragmentary perspective view of a filler used in connection with the inside corner of a prefabricated wall and showing an inside clamp in position relative to the filler; and

Figure 11 is a sectional view taken on the line 11--11 of Figure 3.

In Figures 1-3 inclusive, the numeral 12 designates one corner of a prefabricated form used for the purpose of forming walls of composition material capable of being poured, such for example as concrete. The corner 12 comprises an outside corner section 13 and an inside corner section 14. The outside corner section 13 comprises panels 15 and 16 extending at right angles to one another. As shown in the drawings, the panels 15 and 16 are formed of wood, although it will be understood that these panels may be formed of any material possessing the required rigidity. In detail, each panel comprises a frame 17 and a sheet 18 of plywood suitably secured to the inner side of the frame 17 in order to provide a smooth and uninterrupted surface.

Secured to each panel is a metal waler 19 extending in the direction of length of the panel and having laterally spaced angle members 20. As shown in Figure 6, the angle members 20 are arranged with the horizontal flanges 21 positioned adjacent one another and projecting inwardly with respect to the associated panel. More particularly, the vertical flanges 22 of the angle members 20 project laterally outwardly from the horizontal flanges 21 and lie in a common vertical plane. The flanges 21 are Secured together at longitudinally spaced points by fastener elements 23 in the form of studs and the flanges 21 are held in proper spaced relationship by spacers 24 which may be formed integral with the studs 23 or may be in the form of sleeves respectively mounted on the studs 23 between the horizontal flanges 21. In any case, the frame members of the frame 17 are slotted to receive the walers 19 in a manner such that the outer surfaces of the vertical flanges 22 on the angle members lie flush with the outer surface of the frame 17. The walers are secured to the respective frames 17 of the panels by screws or other fastener elements and in actual practice each panel has two or more walers secured thereto at spaced intervals vertically of the panels.

As shown particularly in Figure 3, the panel 15 overlies the adjacent end of the panel 16 to provide an outside corner and is secured in abutting engagement with s the adjacent end of the panel 16 by clamps Spaced from each other vertically of the panels. In practice, a clamp is associated with each of the vertically spaced walers provided on the panels and one of said clamps is indicated by the numeral 25 in the drawings. The clamp 25 comprises a supporting part 26, a part 27 mounted on the supporting part 26 for sliding movement, a part 28 mounted on the supporting part 26 for sliding movement at right angles to the part 27, and a wedge 29.

As shown in Figures 6 and 9 of the drawings, the supporting part 26 comprises a pair of elongated angle bars 30 having the horizontal flanges 31 secured in vertical spaced relationship to form a guide and having the vertical flanges 32 extending in opposite directions with the inner surfaces located in a common vertical plane.

The flanges 31 are secured in proper vertical spaced re- The spacer 33 is 34 is welded or otherwise permanently secured to the outer edges of the flanges 31. Thus the spacers 33 and 34 also form the opposite sides of the guide provided by the flanges 31 of the angle members 30.

The spacers 33 and 34 terminate short of the outer end of the supporting member 26 to provide clearance for the part 27. The part 27 extends at right angles to the supporting part 26 and is slidable relative to the supporting part between the flanges 31. 'A pin 35 extends vertically through the flanges 31 beyond the outer edge of'the part 27 and a fulcrum member 36 is secured to the supporting part 26 between the flanges 31 in a position to engage the inner edge of the part 27.. The pin 35 and the fulcrum member 36 respectively engage the opposite edges of the part 27 at points spaced lengthwise of the part 27 in order to permit angular movement of the part 27 relative to the supporting part 26.

A rod 37 is welded or otherwise permanently secured to the inner edge of the part 27 adjacent the inner end of the latter part and this rod forms a panel abutment. Also secured to the inner edge of the part 27 is an anchor member 38. The anchor member 38 is positioned at the inner end of the part 27 and is provided with a laterally inwardly opening slot 39, as shown in Figure 3 of the drawings. A vertical pin 40 is provided at the outer end of the part 27 and this pin coacts with the pin 35 and abutment rod 37 to hold the part 27 in assembled relationship with the supporting part 26.

As shown in Figures 3, 6 and 9- of the drawings the part 28 is supported for sliding movement between the flanges 31 on the supporting part 26 and has an anchor member 41 projecting laterally inwardly from the inner end thereof. The edge of the anchor member 41 facing the part 27 is formed with a V-shaped slot 42 and the purpose of this slot will be more fully hereinafter described. In addition, the part 28 is formed with an elongated slot 43 extending in the direction of sliding movement of the part 28 and registerable with slots 44 formed in the flanges 31 of the supporting part 26.

The wedge 29 extends vertically through the slots 43 and 44. The edge 45 of the wedge 29 facing the member 27 tapers inwardly from the top of the wedge to the bottom of the latter and has a cam engagement with the adjacent edge 46 of the slot 43 in the member 28. The opposite edge 47 of the wedge 29 is straight or normal to the flanges 31 and engages the adjacent edges 48 of the slots 44 formed in the flanges 31.

The clamp 25 is installed as shown in Figure 3 of the drawings wherein it will be noted that the supporting part 26 extends along the corner panel 16 in seating engagement with the vertical flanges 22 of the waler 19 associated with the panel 16. As shown particularly in Figure 6 of the drawings, the member 41 projects be tween the flanges 21 of the adjacent waler 19 in a position such that the spacer 24 associated with the end fastener 23 of the waler' 19 abuts the inner tapered surface 49 of the V-shaped slot 42. The arrangement is such that outward sliding movement of the part 28 relative to the supporting part 26 by the wedge 29 not only tends to urge the panel 16 toward the panel but also draws the supporting part 26 into firm clamping engagement with the panel 16. a

It will also be noted from Figure 3 of the drawings that the abutment rod 37 on the part 27 engages the adjacent 'wa-ler 19 on the panel 15 in a position directly opposite the outer end of the panel 16. The spacer 24 associated with the adjacent end fastener 23 of the waler 19 is received in the slot 39 formed in the anchor member 38 on the part 27. I

It follows from the above that when the wedge 29 is forced downwardly to move the part 28 in an outward direction there is a tendency for the supporting part 26 to move inwardly. As a result the inner .end of the part 27 tends to swing about the fulcrum 36 in a 4 direction toward the anchor member 41 and consequently the panel 15 is firmly clamped against the adjacent end of the panel 16. It has been stated above that the part 27 is mounted for sliding movement relative to the supporting part 26 in the directionof length of the part 27. This is advantageous in that it enables effectively clamping the panel 15 to the adjacent end of the panel 16 regardless of the extent to which the panel 15 overlies the adjacent end of the panel 16. In other Words, the panel 15 may be adjusted lengthwise throughout an extent approximating the width of the adjacent end of the panel 16 and thereby compensate for fractional wall dimensions.

The inner surface of the composition wall is formed by panels 50 and 51. These panels are respectively spaced laterally from and extend parallel to the outer panels 15 and 16. The inner panels 50 and 51 are identical in construction. Each inner panel comprises a frame 52, a sheet 53 suitably secured to the outer side of the frame in a manner to form the inner surface of the composition wall, and a waler 54 suitably secured to the inner side of the frame 52. The walers 54 are identical in construction to the walers 19 previously described and are secured to their respective panels in the same manner as the walers 19. Hence, corresponding parts of the walers are indicated by the same reference numerals.

As shown in Figure 3 of the drawings, the adjacent ends of the corner panels 50 and 51 are spaced from each other and are connected by a corner structure indicated generally by the reference numeral 55. The corner structure 55 comprises a filler 56 and inside corner clamps, one of which is indicated by the numeral 57. As shown particularly in Figure 10 of the drawings, the filler 56 comprises a vertical sheet metal column having an inner wall 58 adapted to abut the outer end 59 of the panel 50 and having an outer wall 60 which is transversely curved in a manner to form the composition wall with a rounded inner corner. The outer wall 60 terminates in a flange 61 which overlies the inner surface of the panel 51 ad jacent the outer end 62 of the panel 51. As will be more fully hereinafter described, the filler 55 is clamped to the end 59 of the panel 50 and the end portion 62 of the panel 51 is clamped to the flange 61 by the inside corner clamp 57.

The inside corner clamp 57 comprises a supporting part 63, a pair of parts 64 and 65 slidably mounted on the supporting part 63, and a pair of wedges 66 and 67. In Figures 3, 7 and 11, the supporting part 63 comprises angle members 68 having the horizontal flanges spaced vertically from one another and having the vertical flanges 69 extending in opposite directions in a common vertical plane. Welded or otherwise suitably secured to the free edges of the horizontal flanges is a bar 70 which bridges the vertical space between the horizontal flanges and cooperates with the latter to form a guide for the part 65. A pair of vertically spaced plates 71 are welded.

along one longitudinal edge thereof to the bar 70 and the opposite longitudinal edges of the plates 71 are welded to a bar 72. The bar 72 bridges the vertical space between the plates 71 and cooperates with the latter and with the bar 76 to form a guide for the part 64. The construction is such that the parts 64 and 65 are mounted on the sup porting part 63 for sliding movement along parallel paths.

As shown in Figure 8 of the drawings, the part 64 has a slot 73 elongated in the direction of sliding movement of the part 64 and registrable with elongated slots 74 formed in the plates 71. The wedge 66 projects downwardly through the slots 73 and 74. The outer edge 76 of the vertical wedge 66 is tapered from the upper end of the wedge to the lower end and has a camming engagement with the adjacent edge of the slot 74 in the upper:

most plate 71. The opposite edge 77 of the wedge extends in a straight line substantially perpendicular to the part 64 and has a bearing engagement with the adjacent edge of the slot 73 in the part 64. The arrangement is such that downward movement of the wedge 66. imparts a movement to the part 64 in the direction of the panel 51. It will be noted from Figures 7 and 8 of the drawings that a pair of vertically extending abutment rods 78 are secured to the inner end of the part 64 in lateral spaced relationship and the arrangement is such that these rods abut the adjacent waler 54 on the panel 51, as will be more fully hereinafter described.

As shown in Figure 11 of the drawings, the part 65 has an elongated slot 79 extending in the direction of sliding movement of the part 65 and registrable with elongated .slots 80 formed in the horizontal flanges of the angle members 68. The wedge 67 extends downwardly through the slots 79 and 80. One edge 81 of the wedge 67 tapers downwardly from the upper end of the wedge and has a cam engagement with the adjacent edge of the slot 80 formed in the horizontal flange of the uppermost member 68, and the opposite edge 82 of the wedge extends normal to the part 65 and engages the adjacent edge of the slot 79 in the part 65. With the above arrangement, downward movement of the wedge 'impartsa slidingmovement to the part 65 in a direction toward the panel51.

As shown in Figure 3 of the drawings, an anchor member83 extends laterally outwardly from the part 65 'and is formed with a V-shaped slot 84 which opens toward a hook 85 at the outer end of the supporting part 63. It will be noted from Figure of the drawings that the hook 85 is in the form of a bar permanently WEIdCdOl otherwise secured to the supporting part63.

In use, the clamp 57 is assembled in the manner shown in Figure 3 of the drawings wherein it will be noted that the anchor member 83 is extended between the horizontal flanges 21 of the adjacent waler 54 in a position to engage the spacer 24 associated with the end fastener 23 of the waler 54. More particularly, the spacer 24 is received in the slot 84 and has a camming engagement with the, outer tapered edge of the slot 84 so that movement of the part 65 in a direction toward the end 59 of the panel 54 firmly clamps the supporting part 63 against the Ver tical flanges 22 of the adjacent waler 54. The hook 85 projects into the filler column 56 and is engageable with a vertical pin 86 secured to the filler column 56 by frame members 87. It follows from the above that downward movement of the wedge 67 in effect relatively moves the anchor member 83 and the hook 85 in directions toward one another toetfectively clamp the end wall 58 of the filler column 56 to the adjacent end Wall 59 of the. panel 50.

It will further be noted from Figure 3 of the drawings that when the clamp 57 is installed the abutment bars 78 engage the adjacent waler 54 on the panel 51 at the end 62 of the latter. As a result, downward movement of the wedge 66 effectively clamps the panel 51 against the flange part on the filler column 56. Thus, the corner panels 50 and 51 together with the filler column 56 are firmly and removably clamped together by the clamp 57.

It will be noted from Figure 2 of the drawings that the panel 16 is held in proper spaced relationship to the panel 50 by a spacer 88 comprising an elongated bar having the outer end overlying the top of the panel 16 and having the inner end overlying the top wall 89 of the filler column 56. A stop in the form of an angle member 90 is secured to the underside of the bar 88 in a position to abut the inner surface of the panel 16 and fastener elements 91 are provided for securing the outer. end of the bar 88 to the panel 16. As shown in Figure 4, the inner end of the bar 88 is formed with an opening 92 which is selectively registrable with laterally spaced openings 93 formed in the top wall 89 of the filler column 56, depending on the desired width of the composition wall to be formed between the panels.

The inner end of the bar 88 is held in position by a pin 94 extending through the opening 92 in the bar 88 and through one of the openings 93. The pin 94 is secured at its upper end to the inner end. of a second bar 95 having the outer end overlying the top of the panel 15 and secured thereto by fastener elements 96. An abutment 97 in the form of an angle member is welded or otherwise suitably secured to the underside of the bar 95 in a position to engage the inner surface of the panel 15.

In practice, the inner and outer panels are also secured in lateral spaced relationship by tie rods 98. As shown in Figures l-3 inclusive of the drawings, the inner ends of the tie rods 98 project between the angle members of the walers 54 and the outer ends project between the angle members of the walers 19. The inner ends of the rods 98 have slots therethrough for receiving pins 99 and the upper ends of the pins are shaped to hook over the vertical flanges 22 of the top angle members of the walers 54. The outer ends of the tie rods 98 are also provided with slotsfor receiving pins having hooked portions at the top adapted tohook over the vertical flanges 22 of the top angle members of the walers 19. The rods 98 are tapered from one end to the other in order to facilitate Withdrawingthe rods subsequent to pouring the composition material between the walls of the form.

i It follows from the foregoing that the present invention provides corner clamps rendering it possible to readily and effectively secure both the inside and outside corner panels of a composition wall in place. It will also be noted that the clamps are composed of a relatively few simple parts which are assembled to provide a unitary structure and this feature contributes materially to facilitating both installation and removal of the clamps.

What we claim as our invention is: i

1. A collapsible form for composition walls comprising first and second wall panels extending in angularly related planes with an end of the first panel abutting the inner side of the second panel, adjacent the end of the latter to form a corner, an outside corner clamp for removably securing said panels together in the aforesaid relationship comprising an elongated supporting part extending along the outer side of said first panel outwardly beyond the 'corner formed by said panels, a second elongated part extending transversely of said supporting part along the outer side of said second panel outwardly beyond the corner formed by said panels, the end portion of said second part beyond said corner being supported on thecorresponding end portion of said supporting part for slidingmovement of said second part in the direction of its length, a thirdpart mounted on the opposite end portion of said supporting part for sliding movement along said first panel lengthwise of said supporting part, said third part having a portion engageable with said first panel to urge said first panel in its plane toward said sec- 0nd panel upon movementof said third part along said supporting part toward said second part, actuating means engageable with said supporting and third parts operable to move said third part along said supporting part toward said second part, said second part having means. engageable with said second panel to hold the inner side thereof against the end of said first panel and also to hold part against lengthwise sliding movement relative to said.

supporting part in response to operation of said actuating means.

2. A collapsible form for composition walls comprising first and second wall panels extending in angularly related planes with an end of the first panel abutting the inner side of the secondpanel adjacent the end of the latter to form 'a corner, anoutside corner clamp for removably securing said panels together in the aforesaid relationship comprising an elongated supporting part extending along the outer side of said first panel outwardly beyond the corner formed by said panels, a second elongated part extending transversely of said supporting part along the outer side of said second panel outwardly beyond the corner formed by said panels, means supporting the end portion of said second part beyond said corner on the corresponding end portion of saidsupporting part for sliding movement of said second part in the direction of its length, a third part mounted on the opposite end portion of said supporting part for sliding movement along said first panel lengthwise of said supporting part, said third part having a portion engageable with said first panel to urge said first panel in its plane toward said second panel upon movement of said third part along said supporting part toward said second part, single actuating means for said clamp engageable with said supporting and third parts operable to move said third part along said supporting part toward said second part, said second part having means engageable with said second panel to hold the inner side thereof against the end of said first panel and also to hold said second panel against movement in its plane away from said corner, said supporting means frictionally holding said second part against lengthwise sliding movement relative to said supporting part in response to operation of said actuating means.

3. A collapsible form for composition walls comprising first and second wall panels extending in angularly related planes with an end of the first panel abutting the inner side of the second panel adjacent the end of the latter to form a corner, an outside corner clamp for removably securing said panels together in the aforesaid relationship comprising an elongated supporting part extending along the outer side of said first panel outwardly beyond the corner formed by said panels, a second elongated part extending transversely of said supporting part along the outer side of said second panel outwardly beyond the corner formed by said panels, means supporting the end portion of said second part beyond said corner on the corresponding end portion of said supporting part for sliding movement of said second part in the direction of its length and for swinging movement toward and away from said second panel, said supporting means including an element on the aforesaid end portion of said supporting part engageable with the adjacent side of said second part, another element on said end portion of said supporting part spaced from said first element toward the opposite end of said supporting part and engageable with the opposite side of said second part at a point spaced from the point of engagement of said first element in a direction away from the opposite end portion of said second part to limit swinging movement of said second part away from said second panel, a third part mounted on the opposite end portion of said supporting part for sliding movement along said'first panel lengthwise of said supporting part, said third part having a portion engageable with said first panel to urge said first panel in its plane toward said second panel upon movement of said third part along said supporting part toward said second part, single actuating means for said clamp engageable with said supporting and third parts operable to move said third part along said supporting part toward said second part, said second part having means engageable with said second panel to hold the V inner side thereof against the end of said first panel and also to hold said second panel against movement in its plane away from said corner, said elements engaging said second part in response to operation of said actuating means to prevent swinging movement of said second part away from said second panel and to'frictionally oppose sliding movement thereof in the direction of its length.

4. A collapsible form for composition walls comprising first and second wall panels extending in angularly related planes with an end of the first panel abutting theinner side of the second panel adjacent the end of the latter to form a corner, said first and second panels respectively having first and second anchors adjacent said corner, an outside corner clamp for removably securing said panels together in the aforesaid relationship comprising an elongated supporting part extendingalong the outer side of said first panel outwardly beyond the corner formed by said panels, a second elongated part extending transversely of said supporting part along the outer side of said second panel outwardly beyond the corner formed by said panels, means supporting the end portion of said second part beyond said corner on the corresponding end portion of said supporting part for sliding movement of said second part in the direction of its length and for swinging movement toward and away from said second panel, said supporting means including an element on the aforesaid end portion of said supporting part engageable with the adjacent side of said second part, another element on said end portion of said supporting part spaced from said first element toward the opposite end of said supporting part and engageable with the opposite side of said second part at a point spaced from the point of engagement of said first element in a direction away from the opposite end portion of said second part to limit swinging movement of said second part away from said second panel, a third part mounted on the opposite end portion of said supporting part for sliding movement along said first panel lengthwise of said supporting part, said third part having an anchor engaging member engageable with said first anchor to urge said first panel in its plane toward said second panel upon movement of said third part along said supporting part toward said second part, single actuating means for said clamp engageable with said supporting and third parts operable to move said third part along said supporting part toward said second part, said second part having an abutment engageable with said second panel to hold the inner side thereof against the end of said first panel and also having an anchor engaging member engageable with said second anchor to hold said second panel against movement in its plane away from said corner, said elements engaging said second part in response to operation of said actuating means to prevent swinging movement of said second part away from said second panel and to frictionally oppose sliding movement thereof in the direction of its length.

5. A collapsible form for composition walls comprising first and second wall panels extending in angularly related planes with an end of the first panel abutting the inner side of the second panel adjacent the end of the latter to form a corner, said first and second panels respectively having first and second anchors adjacent said corner, an outside corner clamp for removably securing said panels together in the aforesaid relationship comprising an elongated supporting part extending along the outer side of said first panel outwardly beyond the corner formed by said panels, a second elongated part extending transversely of said supporting part along the outer side of said second panel outwardly beyond the corner formed by said panels, means supporting the End portion of said second part beyond said corner on the corresponding end portion of said supporting part for sliding movement of said second part in the direction of its length and for swinging movement toward and away from said second panel, said supporting means including an element on the aforesaid end portion of said supporting part engageable with the adjacent side of said second part, another element on said :end portion of said supporting part spacedfrom said first element toward the opposite end of said supporting part and engageable with the opposite side of said second part at a point spaced from the point of engagement of said first element in a direction away from the opposite end portion of said second part to limit swinging movement of said second part away from said second panel, a third part mounted on the opposite end portion of said supporting part for sliding movement along said first panel lengthwise of said supporting part, said third part having an anchor engaging member engageable with said first anchor to urge said first panel in its plane toward said second panel upon movement of said third part along said supporting part toward said second part, said supporting and third-parts having registrable slots elongated in the direction of length of said supporting part, single actuating means for said clamp in the form of a Wedge extending through said slots and operable to move said third part along said supporting part toward said second part, said second part having an abutment engageable with the outer side of said second panel to hold the inner side thereof against the end of said first panel and also having an anchor engaging member engageable with said second anchor to hold said second panel against movement in 15 2,526,529

its plane away from said corner, said elements engaging said second part in response to operation of said actuating wedge to prevent swinging movement of said second part away from said second panel and to frictionally oppose sliding movement thereof in the direction of its length.

References Cited in the file of this patent UNITED STATES PATENTS 1,538,496 Wells May 19, 1925 1,590,033 Keffer June 22, 1926 1,780,661 Wedberg Nov. 4, 1930 Arrighini et a1. Oct. 17, 1950 

